Detection flags (7 columns)

SUM_FLAG (Integer)

The summary flag is an integer representation of the stacked source flags. For a clean detection, all strings are ``F'', and the summary flag is ``0''. The first ten components of the string flag encode low PSF coverage, a detection close to a bright point-like or close to an extended source, a detection close to a bad CCD area, each of which is summarised by a SUM_FLAG=1; a probably spurious detection which is close to a bright detection or which is significant in only one band or which is on a warm pixel each of which is summarised by a SUM_FLAG=2. The eleventh character of the EP_FLAG indicates the result of visual screening, during which the screeners mark problematic detector areas like single reflection patterns and largely extended background emission. It translates into a SUM_FLAG=3 and to SUM_FLAG=4 if it is associated with one of the spurious or warm pixel flag (see Tables).

Table 3.1:  Meaning of the characters in the quality flags PN_FLAG, M1_FLAG, M2_FLAG, EP_FLAG and their distribution in 5XMM-DR15.
Flag Description EP PN M1 M2
all 818656 100% 753847 100% 692614 100% 777900 100%
0 No warning issued 537679 66% 550693 73% 594018 86% 679272 87%
1 PSF coverage $<$ 50% 160445 20% 97178 13% 42025 6% 41749 5%
2 Near a bright point-like source 4090 0% 3875 1% 3588 1% 3876 0%
3 Near a bright extended source 60955 7% 56180 7% 54894 8% 58519 8%
4 Extended near a bright point source 728 0% 683 0% 629 0% 675 0%
5 Extended near a bright extended source 12201 1% 8203 1% 9917 1% 11088 1%
6 Extended, significant in one band 6146 1% 5467 1% 5644 1% 5862 1%
7 Extended, flag 4, 5, or 6 14605 2% 11699 2% 12654 2% 13694 2%
8 On a bad pixel or CCD area 24433 3% 24342 3% 170 0% 34 0%
9 Near a bad CCD area 65913 8% 65711 9% 476 0% 268 0%
10 On a warm CCD pixel 13662 2%
11 Flagged during visual screening 54516 7%

Table 3.2: Meaning of the SUM_FLAG values
Value Description
0 Good
1 if the warning flags EP_FLAG 1, 2, 3 or 9 set to true but not 7, 8, 10 or 11
2 if the possibly-spurious or warm pixel flags EP_FLAG 7, 8 or 10 set to true but not the manual flag 11
3 if the manual flag EP_FLAG 11 is set to true but not the spurious or warm pixel flags 7, 8 or 10
4 if the manual flag 11 as well as one of the spurious or warm pixel flags 7, 8 or 10 are set to true

EP_FLAG (String) SAS task dpssflag


EPIC flag string made of the flags 1 - 11 (counted from left to right): it combines the flags in each camera ((PN_FLAG, M1_FLAG, M2_FLAG), that is, a flag is set in EP_FLAG if at least one of the camera-dependent flags is set. The 11th flag results from the manual screening, see tables. See 2XMM UG Sec. 3.1.2 h) and Sec. 3.2.6  for a detailed description of the flags.

PN_FLAG (String) SAS task dpssflag


PN flag string made of the flags 1 - 10 (counted from left to right) for the PN source detection. A flag is set to True according to the conditions summarized in Tab. 3.1 for the automatic flags, and Tab. 3.1 for the manual flags. In cases where the camera was not used in the source detection a dash is given. Where a source was not detected by the PN the flags are all set to False (default).

M1_FLAG (String) SAS task dpssflag


MOS1 flag string made of the flags 1 - 10 (counted from left to right) for the MOS1 source detection. A flag is set to True according to the conditions summarized in 4XMM UG Tab. 3.1 for the automatic flags, and Tab. 3.1 for the manual flags. In cases where the camera was not used in the source detection a dash is given. Where a source was not detected by the MOS1 the flags are all set to False (default).

M2_FLAG (String) SAS task dpssflag


MOS2 flag string made of the flags 1 - 10 (counted from left to right) for the MOS2 source detection. A flag is set to True according to the conditions summarized in 4XMM UG Tab. 3.1 for the automatic flags, and Tab. 3.1 for the manual flags. In cases where the camera was not used in the source detection a dash is given. Where a source was not detected by the MOS2 the flags are all set to False (default).

TSERIES (Boolean)

The flag is set to True if this detection has a time series made in at least one exposure (cf. Sec. 3.6). There is no flag on a source basis.

SPECTRA (Boolean)

The flag is set to True if this detection has a spectrum made in at least one exposure (cf. Sec. 3.6). There is no flag on a source basis.

5XMM-DR15 Catalogue Table: Version June 2026